>>32980479Thing is, it doesn't need to do damage. It is a pokémon that only needs to set toxic spikes, pray for scald burn, recover its injuries off, then switch out and let regenerator do the rest. Occasionally haze a setup sweeper, too.
It is so bulky that a fully physically defensive variant cannot be OHKOed by any strong physical attacker in OU, 2HKOed at best by those with EQ STAB, and vice versa for the fully specially defensive variant and strong special attackers, except koko and lele under their terrains. Regenerator is so serviceable to this role that considering merciless is laughable.
An offensive toxapex is the same as an offensive chansey: is not that you can't get away with it sometimes, it's just you're losing on so much more potential of what the mon can actually do (even if what they do best is stall).